[ietf79-tech] RCS for configuration files

[Bill Fenner]

Here's a quick summary of how to use RCS for configuration files
(which we are generally trying to do on services1, services2,
management):

Normal flow:
- When you decide to edit a file, check it out:
  co -l <foo>
- When you are done editing, check it back in:
  ci -u <foo>

Exception flow:
- If the file is already writable, but not locked (e.g., "co -l" gripes at you):
  - Use rcsdiff to see what the changes are
  rcsdiff -u <foo>
  - (Probably) check in the changes
  rcs -l <foo>
  ci -u <foo>
- If you checked in with just a plain "ci", it will have helpfully
deleted the file.  To recover:
  co -u <foo>

Generally, "-l" means to lock the file; "-u" means to unlock it,
except that rcsdiff uses "-u" for unified diff output.

  Bill